Composite structures such as those used in the automotive, marine and aerospace industries may be fabricated using automated composite material application machines, commonly referred to as automated fiber placement (AFP) machines. AFP machines may be used in the aircraft industry, for example to fabricate structural shapes and skin assemblies by wrapping relatively narrow strips of composite, slit tape or “tows”, collimated into a wider band, around a manufacturing tool. The AFP machine aligns and places a plurality of tape strips, typically six or more, in continuous, edge to edge contact forming a single wide, conformal bandwidth which is placed on and compacted against the tool.
In order to fabricate large, complex laminated composite assemblies, current AFP machines may use fiber placement heads having a relatively high degree of operational flexibility. For example, current placement heads may have the ability to add drop-off or cut any or all of the contiguous tape strips independently of all others by providing separate, independently controllable cutters for each tape strip. Current placement heads therefore may be relatively complex, large and heavy.
The size, weight and complexity of current placement heads may preclude their use in fabricating relatively small composite laminate assemblies, or in fabricating layups that require relatively high placement resolution. Moreover, because of their complexity, current placement heads are relatively expensive.
Accordingly, there is a need for automatic fiber placement apparatus that has reduced mechanical complexity and is both smaller in size and lighter in weight for those fiber applications requiring higher placement resolution and/or simplified tape application. Further, there is a need for a method of fiber placement using less complex placement machines that allows fiber placement forming ramped or contoured tape patterns.